Context and objectives. The use of force by police officers toward individuals in a state of mental disturbance is at the heart of many debates. The actual unfolding of the police interventions, and the transformation of a situation into one requiring the use of force are also amongst current concerns. Collaborating with the Sherbrooke Police Department (Québec), this two-parts project first considers drawing up the script of police interventions with people in state of mental disturbance. Then, it identifies elements that affect the use of force. Methodology. Data was collected from event reports and database on police information (n=130). Details about the environment, the policemen's actions, and the individual's reaction were noted. Descriptive and comparative analyses were then conducted. Results. The script of police interventions with individual in a state of mental disturbance is organized in 8 phases according to the usual script model, from the preparation to intervene, then the intervention itself, to the follow-ups of the intervention. The most important factors to diminish the use of intermediary or armed force are: officers look for an alternative solution to the use of force; someone entertaining a good relationship with the individual is on location; the individual cooperates; and the use of force was first initiated by the officers. The elements augmenting the risks of intermediary or armed force are: a high average of violent behaviours displayed by the individual; the fact no communication was possible with the individual; the fact the officers had to be strict; and when the individual refuses to cooperate. Conclusion and implications for prevention. Drawing up scripts for the police interventions with individuals in a state of mental disturbance allows a better understanding of the intervention's process and it allows noting the importance of interactions between the different actors of the script. The individual's actions considerably affect the officers' decisions leading to the use of force, or rather allow for the situation to be resolved without force. The results and the method used can be considered for police training, and for administrative measures regarding safety matters.